I got a modified ST70 from Blair. It has replacement output transformers that I measured out to read 8K with a single 8 ohm output. The power transformer is 150 volt at about 600 - 700ma, good for a doubler, 6.3 volts at somewhere between 5 and 8 amps and a bias voltage.
What tubes to use with it? I was originally thinking 1625s since I have about 30 of them and it would make matching easier, but I would have to enlarge the socket holes for the pins to fit, plus drill more holes for the socket screws. Then I though of rebasing them to octals for a quasi 12BG6, but that would be a lot of work. It's difficult removing the glass from a socket on one tube, and I have to do 4 1625s and 4 bad octals. Plus I would rather not use anode caps.
What tubes to use with a 25 watt or so 8K output transformer of a ST70?